An attorney for the initiative says the lawsuit is likely to fail because opponents are on thin legal ground.

One big hurdle is the state hasn’t certified a lab to test the dispensaries’ products.

Operators say it’s the start of new business they hope will bring high-quality, and formerly unavailable, medicine to patients who need it the most.

The suit was brought by 13 groups and individuals including Maricopa County Attorney Bill Montgomery and Yavapai County Attorney Sheila Polk.

Gov. David Ige signed a bill Monday, facing a shortage of doctors willing to certify patients.

Supporters of a ballot initiative that would legalize cannabis for medical purposes turned in about 17,600 signatures Monday, saying they were confident their efforts would put the issue to a statewide vote.

Most pharmacists haven’t signed on to the country’s pioneering cannabis program, citing security concerns and complaining of paperwork, cost increases or opposition from customers.

Attorneys want to know whether lawyers can use medical cannabis, own or operate medical cannabis businesses and represent cultivators, processors, dispensaries, patients and caregivers.

Minnesota’s final two medical marijuana dispensaries are set to open Friday, bringing all eight clinics online ahead of a critical expansion that could bring thousands more patients into the program.

Canada launched a task force Thursday to study the regulation of recreational marijuana ahead of a legalization measure the government plans to send to parliament next spring.